Multiple wheel counting device



July 16, 1963 H. H. HARADA MULTIPLE WHEEL COUNTING DEVICE Filed Jan. 15, 1962 HQVENTOR.

flezzgy (5, rVam'ak vBY United States Patent 3,097,792 MULTIPLE WHEEL COUNTING DEVICE Henry H. Harada, Grand Blanc, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Jan. 15, 1962, Ser. No. 166,207 8 Claims. (Cl. 235-117) This invention relates to counting devices and more parrticularly to instruments such as odometers which include coaxially mounted numeral wheels.

'It is customary in the field of automotive mileage indicating devices such as odometers to transfer the rotation count of a numeral wheel by way of a pinion gear to the next numeral wheel of higher order. Successive wheels are so driven by pinion gears and each gear is customarily supported by a pinion carrier fixed in position between each set of adjacent numeral wheels. Heretofore, arrangements of this type have been such that friction has developed in operating the counting devices. This friction is negligible but adequate to influence the operationi.e.--it adversely affects the smoothness of operation. Such adverse a condition is appreciated in the disclosure of the United States Patent 1,826,391, granted October 6, .1931, in the name of C. B. Dinsmore. In that patent, the hubs of adjacent numeral wheels engage, tending by friction to rotate each successive wheel at the same time as rotation is imparted to the latter by a pinion gear, but each pinion gear tends to cock and the numeral wheels tend axially to separate and wobble during the rotation transfer period. These conditions become more severe because of cumulative wear and tend to reduce the otherwise expected useful life of the device.

An object of the present invention is to provide an improved multiple wheel counting device in which cocking or misalignment of parts in prevented and longevity of the device in service is assured.

A feature of the invention is a counting device having numeral wheels with nesting lhubs. Another feature is such a device having pinion gears each of which is radially positioned by annular shoulders on adjacent numeral wheels, these shoulders facing outwardly from the common axis of the wheels.

These and other important features of the invention will now be described in detail in the specification and [then pointed out more particularly in the appended claims.

In the drawings:

FIGURE 1 is an elevation view of an odometer wheel assembly largely concealed by a panel and in which assembly the present invention is embodied;

FIGURE 2 is an enlarged view, partially in section, of the right-hand end portion of the assembly shown in FIG- UREl;

:FIGURE 3 is an enlarged sectional view of a pinion gear arrangement shown in FIGURE 2; and

FIGURE 4 is a sectional view looking in the direction of the arrows 4-4 in FIGURE 2.

As is customary in devices of the type herein considered, a wheel assembly indicated generally at includes a shaft 12 coaxially retaining a first numeral wheel 14 and a last numeral wheel 16 as well as intermediate numeral wheels 18. The shaft 12 is provided with an annular thrust ring 20 at one end and a second annular ring 2-2 at the other end. A coil spring 24 is preferably but not necessarily used between the last wheel 16 and the ring 22 to retain the coaxial wheels in contacting relationship and against the thrust ring 20. The first wheel 14 bears an extended hub portion 30 bearing an annular series of gear teeth 32 thereon for engagement with a driving mechanism such as a gear and cable arrangement connected to the transmission of an automobile. The

3,097,792 Patented July 16, 1963 "ice numeral wheels have male hub portions 36 journaled on the shaft 12 and these portions are so arranged as to serve as bearings for female hub portions 38. In the assembly of the wheels the ends of the male hub portion 36 are adapted frictionally to engage shoulder portions 40 formed on the adjacent wheels. The annular end surface 42 of each female hub portion 38 is spaced a given distance from an annular surface 44 on an adjacent male hub portion. Because of this spacing, there is clearance or more than enough room for the web portion of a pinion carrier 46-. A side view of this pinion carrier is best seen in FIGURE 4, its outer diameter being equal to that of the numeral wheels and its periphery being supplied with a notched tab 48 by means of which the pinion carrier may be held by exterior structure in a non-rotative position with respect to the axis of the shaft 12 and the numeral wheels of the counting device. The pinion carrier has a notch 50 in its periphery freely to receive and retain a cylindrical disk portion 52 of a pinion gear 55. The pinion gear carrier 46 also bears arcuate ridges 58 one being on each side of the pinion carrier. These arcuate ridges for each pinion carrier are limited in arcuate extent as best seen in FIGURE 4 thereby opposingly to contact the hubs 60 and 62 of the corresponding pinion gear. Because of this contact with hubs 60 and 62, the pinion gear 55 is bodily held in a predetermined fixed position by one of the tabs 48.

Each numeral wheel does not engage the shaft for its full hub length but is relieved as at 66 or 68 to prevent any possible binding.

The interior left rim of each numeral wheel is supplied with two driving teeth '70 for engaging appropriate teeth 72 formed on a pinion gear 55. The other side of each pinion gear 55 is also provided with teeth 74 for engaging a full circular series of teeth 76 formed inside the righthand rim of the adjacent or driven wheel. The specific design of the teeth in the pinion gear and wheels is of no moment here but may be like that commonly known in this field. The smooth surfaced hub portions 60 and 6-2 above mentioned are cylindrical in form and are received within annular recesses 84 and 86 formed in the adjacent wheels.

Assuming that the assembly 10 of numeral wheels and shaft 12 is mounted behind the instrument panel of an automobile and properly in registry with an opening 82 in the panel for viewing by an operator, data indicating the miles traveled by the vehicle involved may be transmitted by the cable and gear arrangement customarily used to convey rotation to the teeth 32 of the first numeral wheel 14. At the tenth revolution of this wheel, the pinion gear will cause the rotation of the second or adjacent numeral wheel 18' so that the latter will rotate one digit for every ten revolutions of the first wheel and after ten revolutions of the second wheel the third wheel 18 will be rotated one digit to indicate revolutionsall as is customary in such devices.

It will be noted that the male hub portions 36 and the female hub portions 38 are so arranged with respect to each other that, if desired, the shaft 12 could be omitted entirely. The wheel hubs are actually in nested arrangement and suppont each other. The broad hub support thus supplied to each wheel inhibits any wobbling or noncoaxial movement of the series of wheels and because of this firm coaxial arrangement, there is no possibility of the pinion gears 55 cocking during transfer periods of rotative motion. When the teeth of the pinion gears and the numeral wheels mesh to transfer motion, the pinion gears tend to move inwardly but are stopped by the shoulders '90 and 92 formed on adjacent numeral wheels. The arcuate ridges 58 are made free of these shoulders and as best seen in FIGURE 2.

With this construction, all the parts in the counting device except the spring 24 may be made of plastic and such plastic may be nylon, or it may be a butadiene, styrene, acrylonitrile interpolymer. These plastics are given merely as suitable examples.

A most important advantage in the odometer wheel assembly is in the nature of the pinion carrier plates 46. It will be noted that each plate 46 does not need to be cut accurately as the numeral wheels take the load transmitted by the pinion gears. In devices of this nature as heretofore provided, the numeral wheels and elements for holding the pinion gears are necessarily made with a high order of accuracy which fact is reflected in the cost.

I claim:

1. A multiple wheel counting device comprising a shaft, two numeral wheels having hubs coaxial with said shaft, one of said hubs having a reduced diameter portion constituting a male portion journaled on said shaft, the other of said hubs having an annular portion constituting a female portion journaled on said reduced diameter portion, a fixed pinion carrier mounted between facing portions of said wheels and surrounding said male portion, a pinion gear rotatably retained by said pinion carrier to serve as a transfer mechanism of rotative motion between said wheels, and the end of said male portion engaging said other hub to determine clearance space for said two numeral wheels as measured in a direction parallel with the axis of said shaft and relative to said pinion carrier and pinion gear.

2. A multiple wheel counting device, numeral wheels coaxially mounted therein and having coaxial hubs, one of said hubs on one of said wheels having a male portion, the other of said wheels having a hub with a female portion journaled onsaid male portion, a fixed pinion carrier mounted between said two wheels and surrounding said male portion, a pinion gear having a circular portion rotatably retained by said pinion carrier to serve as a transfer mechanism of rotative motion between said wheels, and the end of said male portion engaging said other wheel'to determine clearance space for said two wheels as measured in a direction parallel with the common axis of said wheels and relative to said pinion carrier and pinion gear.

3. A multiple wheel counting device as set forth in claim 2, said gears having annular shoulders for supporting said pinion gear against motion of the latter toward the common axis of said annular wheels.

T tions, a fixed pinion carrier surrounding each of said male hub portions and interposed between adjacent wheels, a peripheral notch in said carrier, a pinion gear having a circular portion freely retained within said notch, opposed hubs onsaid pinion gear, said carrier having opf posed. surfaces in registry with said notch and engaging said opposed pinion hubs, the said male and female hub portions being arranged to determined running clearances for said wheels and pinion gear in the direction of the axis of said wheels, and teeth on said adjacent wheels positioned to serve as a means for transferring rotary motion through said pinion gear.

6. A counting device as set forth in claim 5, said wheels, pinion carrier and pinion gear being made of plastic material.

7. A counting device as set forth in claim 5, said two adjacent wheels having annular shoulders arranged to restrain motion of the said opposed hubs of said pinion gear toward the axis of said wheels.

8. A counting device as set forth in claim 5, a shaft,

. the male hub portions of said numeral wheels being journaled on said shaft, and other portions of said numeral wheels being coaxial with said shaft and'cooperating with the latter in defining annular clearance spaces to promote free running of said wheels with respect to said shaft.

References Cited in the file ofthis patent 8 UNITED STATES PATENTS 1,692,489 Dinsmore Nov. 20, 1928 1,710,229 Mac-Neil Apr. 23, 1929 1,797,738 Tittensor Mar. 24, 193-1 2,628,779 Bliss Feb. 17, 1953 2,658,685 Harada Nov. 10, 1953 2,753,116 Manke July 3, 1956 3,002,687 Herr Oct. 3, 1961 FOREIGN PATENTS 559,256 'Italy Mar. '16, 1957 809,860 Germany Aug. 2, 1951 

1. A MULTIPLE WHEEL COUNTING DEVICE COMPRISING A SHAFT, TWO NUMERAL WHEELS HAVING HUBS COAXIAL WITH SAID SHAFT, ONE OF SAID HUBS HAVING A REDUCED DIAMETER PORTION CONSTITUTING A MALE PORTION JOURNALED ON SAID SHAFT, THE OTHER OF SAID HUBS HAVING AN ANNULAR PORTION CONSTITUTING A FEMALE PORTION JOURNALED ON SAID SHAFT, THE TION, A FIXED PINION CARRIER MOUNTED BETWEEN FACING PORTIONS OF SAID WHEELS AND SURROUNDING SAID MALE PORTION, A PINION GEAR ROTATABLY RETAINED BY SAID PINION CARRIER TO SERVE AS A TRANSFER MECHANISM OF ROTATIVE MOTION BETWEEN SAID WHEELS, AND THE END OF SAID MALE PORTION ENGAGING SAID OTHER HUB TO DETERMINE CLEARANCE SPACE FOR SAID TWO NUMERAL WHEELS AS MEASURED IN A DIRECTION PARALLEL WITH THE AXIS OF SAID SHAFT AND RELATIVE TO SAID PINION CARRIER AND PINION GEAR. 